This invention relates to a high-speed transmission connector and, in particular, to a ground structure of the high-speed transmission connector.
An electrical connector is used to connect two electrical apparatuses. Particularly when a signal is transmitted at a high speed, shielding is required for preventing leakage of the signal and entrance of noise. In case of a connector for connecting two circuit boards to each other, a simple ground structure as a shield is important.
Referring to FIGS. 1A through 1F, description will be made of an assembling process of an existing high-speed transmission connector having a shielding ground structure. In the illustrated example, the high-speed transmission connector is a plug connector having socket contacts for transmitting signals therethrough, which will be referred to as signal socket contacts.
At first referring to FIG. 1A, a plurality of sets of four signal socket contacts 42A through 42D for use in the plug connector (41 in FIG. 1F) are connected to a plurality of arms 43A protruding from a carrier 43, respectively. Each of the signal socket contacts 42A through 42D has a substantially L shape. Such a plurality of sets of the signal socket contacts 42A through 42D connected to the carrier 43 are prepared by pressing a single metal plate.
Next referring to FIG. 1B, the signal socket contacts 42A through 42D in each set are subjected to insert-molding by the use of an insulating resin material to form a contact module 44.
Subsequently, the signal socket contacts 42A through 42D in each contact module 44 are separated from the arm 43A of the carrier 43. As illustrated in FIG. 1C, four ground plates 45A through 45D are incorporated into the contact module 44 on opposite sides thereof, two on one side and two on the other side. Specifically, the ground plates 45A through 45D are press-fitted into grooves formed in the contact module 44. The ground plates 45A through 45D correspond to the signal socket contacts 42A through 42D, respectively. The ground plates 45A through 45D are alternately arranged on the opposite sides of the contact module 44. Specifically, the ground plates 45A and 45C corresponding to the signal socket contacts 42A and 42C are arranged on one side of the contact module 44 while the ground plates 45B and 45D corresponding to the signal socket contacts 42B and 42D are arranged on the other side of the contact module 44.
Turning to FIG. 1D, a shield plate 46 bent into a generally L shape is prepared. Into the shield plate 46, the contact modules 44 with the ground plates 45A through 45D incorporated therein are provisionally inserted one by one. After the contact modules 44, six in total, are inserted, they are collectively press fitted. Then, an assembly illustrated on a left-hand side in FIG. 1E is obtained.
Finally, the assembly including the six contact modules 44 and the shield plate 46 are press fitted into a housing 47 to complete the socket connector 41 as illustrated in FIG. 1F.
Thus, the socket connector 41 includes the six sets of the signal socket contacts 42A through 42D as the six contact modules 44. Among the six sets of the signal socket contacts 42A through 42D, the four sets located inside are shielded by the ground plates on both of the left and the right sides. However, the signal socket contacts 42B and 42D of the leftmost set are not shielded on the left side by the ground plates. Likewise, the signal socket contacts 42A and 42C of the rightmost set are not shielded on the right side by the ground plates. Therefore, the leftmost and the rightmost sets are not practically used.
It is therefore an object of this invention to provide a high-speed transmission connector in which all of signaling contacts including outermost ones are shielded by grounding plates so as to reliably transmit a high-speed signal.
According to this invention, the following structures are provided:
1. A high-speed transmission connector comprising an insulating connector housing, a plurality of contacts fixed to the connector housing at positions forming a plurality of rows and a plurality of columns in a matrix arrangement, and a shield attached to the connector housing, wherein:
the shield comprises a plurality of first ground plates extending in parallel to the columns of the contacts and a plurality of second ground plates extending in parallel to the rows of the contacts;
at least either one ground plates of the first ground plates and the second ground plates being provided with contacting portions to be connected to the other ground plates, one of each of the first ground plates and each of the second ground plates having at least one ground terminal to be connected to an external circuit;
the first ground plates being arranged at an outside of opposite outermost ones of and between every two adjacent ones of the columns of the contacts, the second ground plates being arranged at an outside of opposite outermost ones of and between every two adjacent one of the rows of the contacts, the first and the second ground plates surrounding the contacts and forming a grid structure.
2. A board connector to be mounted on a circuit board, the connector being a high-speed transmission connector for use in connecting a signal circuit of a differential signal transmission system in which a single differential signal is transmitted through each air of two adjacent ones of a plurality of contacts, the connector comprising:
an insulating connector housing provided with a plurality of contact holding holes arranged in a matrix fashion to form a plurality of columns and a plurality of rows including two upper rows and two lower rows, a plurality of first slits formed between every two adjacent ones of and at the outside of opposite outermost ones of the columns of the holding holes and extending in parallel to the columns, and a second slit formed between the two upper rows and the two lower rows of the holding holes and extending in parallel to the rows;
a plurality of contacts fixed to the contact holding holes, respectively;
a plurality of ground plates inserted into the first slits, respectively; and
a second ground plate inserted into the second slit and brought into contact with the first ground plates.
Each of the contacts has a contact lead terminal to be connected to a circuit pattern on the circuit board. Each of the first ground plates has first, second, and third ground terminals which are to be connected to a ground pattern of the circuit board. The contact lead terminals are arranged to form a plurality of columns and plurality of rows in a matrix arrangement. The first, the second, and the third ground terminals are arranged at the outside of opposite outermost ones of and between every two adjacent ones of the columns of the contact lead terminals in a direction parallel to the columns. The first ground terminals of the first ground plates are arranged at the outside of the first row of the contact lead terminals in parallel to the first row. The second ground terminals are arranged between the second and the third rows of the contact lead terminals in parallel to the second and the third rows. The third ground terminals are arranged at the outside of the fourth row of the contact lead terminals in parallel to the fourth row.
3. A high-speed transmission connector for use in connecting a signal circuit of a differential signal transmission system in which a single differential signal is transmitted through each pair of two adjacent ones of a plurality of contacts. The connector comprises:
an insulating connector housing having a plurality of contact holding holes arranged in a matrix fashion to form a plurality of columns and a plurality of rows including two upper rows and two lower rows. A plurality of first slits are formed between every two adjacent ones of and at the outside of opposite outermost ones of the columns of the holding holes and extending in parallel to the columns. A second slit is formed between the two upper rows and the two lower rows of the holding holes and extending in parallel to the rows.
A plurality of contacts are fixed to the contact holding holes, respectively.
A plurality of first ground plates are inserted into the first slits, respectively.
A second ground plate is inserted into the second slit and brought into contact with the first ground plates.
Each of third ground terminals of the second ground plate has a pair of wing portions formed at its base to protrude towards adjacent columns of the contact lead terminals on opposite sides. Each of the contact lead terminals of the contacts and the ground terminals of the first ground plates is formed into a press-fit portion. Each of the first ground plates is integrally coupled with an insulator by press-fitting or insert-molding to form a ground plate module. The ground plate modules are inserted into the connector housing at the outside of the opposite outermost ones of and between every two adjacent ones of the columns of the contacts. The connector is attached to the circuit board by incorporating the ground plate modules into the connector housing in a state when lower ends of the insulators of the ground plate modules are brought into contact with upper ends of the wing portions and then pressing the ground plate modules to the circuit board.